Working days calculator

The rule is the one most payroll and project tools use: take every day after the start date up to and including the end date, keep the Mondays to Fridays, then subtract any that appear in the selected holiday list. Turn on 'include start day' when the start date itself should count, for example the first day of a contract. A holiday on a Saturday or Sunday is already excluded by the weekend rule; what matters is the weekday it is observed on, which is why the US table shows Independence Day 2026 as Friday July 3 and the Korean table lists substitute days.

Formula, for checking: working days = weekdays in the span − weekday holidays in the span. A span that is a multiple of 7 days can be checked by hand: 112 days is 16 weeks and always holds 80 weekdays whatever day it starts on; 35 days is 5 weeks and 25 weekdays.

The eleven federal holidays are set by 5 U.S.C. § 6103 and published each year by the Office of Personnel Management. For federal employees, a holiday on a Saturday is observed the Friday before; on a Sunday, the Monday after. Banks observe the same eleven days but not the same Saturday rule: the Federal Reserve publishes that its Banks and Branches stay open on the Friday before a Saturday holiday, the day federal offices are closed. The stock market differs again — the NYSE closes on Good Friday (April 3, 2026) but stays open on Columbus Day and Veterans Day. This calculator uses the federal-employee dates, so a Saturday holiday is excluded on the Friday before.

Korean public holidays come from the Regulation on Public Holidays of Government Offices, kept by the Ministry of Personnel Management, and since 2022 they are paid days off in every workplace with five or more employees. Labour Day (May 1) and Constitution Day (July 17) were added to that regulation in April 2026 and count from 2026, which is why calendars printed earlier do not show them. Substitute holidays apply when March 1, Buddha's Birthday, Children's Day, Labour Day, Constitution Day, Liberation Day, National Foundation Day, Hangul Day or Christmas falls on a weekend, and when Seollal or Chuseok overlaps a Sunday or another holiday — a Saturday alone does not count for those two. New Year's Day and Memorial Day get no substitute at all. 2026 also has a nationwide local election on Wednesday June 3, a public holiday under the Public Official Election Act.

October 1 to October 31, 2026 (US): 30 days after the start date, 21 of them weekdays; Columbus Day on Monday October 12 comes off, leaving 20 working days. September 4 to December 25, 2026 (US): 112 days, 80 weekdays, minus Labor Day, Columbus Day, Veterans Day, Thanksgiving and Christmas Day itself, giving 75. September 4 to October 9, 2026 (Korea): 35 days, 25 weekdays, minus Chuseok on Thursday and Friday September 24–25, the substitute holiday on Monday October 5 and Hangul Day on Friday October 9, giving 21. An end date that is a holiday is removed, as in the last example.

Shipping estimates like '5–7 business days' mean weekdays that are not carrier holidays; USPS follows the federal list exactly and UPS and FedEx come close. Bank transfers settle on Federal Reserve business days, so an ACH payment sent the Friday before Labor Day lands on Tuesday. Deadlines have their own rule: under US federal and most state court rules, a deadline landing on a weekend or holiday rolls to the next business day, and Korea's Civil Act Article 161 does the same for a period ending on a Saturday or public holiday. Korean payroll treats Saturday as an unpaid day off and Sunday as the paid weekly rest day, so 'working days' in a Korean contract almost always means Monday to Friday minus public holidays, the count this tool gives.

Only national calendars are included. US state holidays such as Patriots' Day in Massachusetts or Good Friday in a dozen states are not subtracted, nor are company floating holidays or the day after Thanksgiving. Korea sometimes declares temporary holidays on short notice, as it did for January 27 and October 10, 2025; those appear only once the list is updated. Half days count as full working days. For other countries, choose 'weekdays only' and subtract local holidays by hand.